1. Field
The present disclosure relates generally to aircraft and, in particular, to operating unmanned aerial vehicles (UAVs). Still more particularly, the present disclosure relates to the automatic calculation of a heading from an automatically determined wind correction angle by the use of a constant bank angle to reduce repeated course corrections when a cross wind is not accounted for along a flight route.
2. Background
Wind is an environmental factor that may affect the flight of an aircraft. For example, a tailwind is a wind that blows in the direction of travel of the aircraft. A tailwind may increase the relative ground speed of the aircraft and may reduce the total time required to reach a destination. In contrast, a headwind blows against the direction of travel of an aircraft and may have the opposite effect.
Other types of winds also may affect the ground track for the flight of an aircraft. A ground track is the path of the aircraft on the surface of the Earth directly below the aircraft. More specifically, a ground track may be the intended course or direction of travel over the surface of the Earth with respect to north. For example, a crosswind is a portion of the wind that may cause an aircraft to drift off course. The heading is the direction in which the longitudinal axis of the aircraft is pointing in relation to magnetic north.
Adjustments may be made to the heading of the aircraft in response to a crosswind such that a course along an intended ground track is maintained. These adjustments typically include having knowledge of the direction and speed of the wind.
Typically, information about winds may be calculated from information obtained through the use of a weather balloon. The information obtained from the weather balloon may be used by a ground location, such as an air traffic control service. The weather balloon contains equipment configured to record the position of the weather balloon at different locations. The weather balloon may also be configured to record other information, such as speed and direction of the wind, as the weather balloon travels through the atmosphere.
These weather balloons, however, may not provide as much information as desired about the winds. For example, a weather balloon typically only gives a vertical profile of winds. Additional weather balloons may be used to provide information about the wind in larger areas. This use of weather balloons may be more expensive and time consuming than desired. Additionally, the use of weather balloons also may be less feasible over areas, such as those that are used as flight corridors for commercial aircraft. In the case of flight operations of unmanned aerial vehicles, course routing may occur over or within airspace in which information about the wind is not available.
Further, to receive information about the wind from a secondary source, the aircraft requires hardware configured to receive the information from an air traffic control service. In the case of unmanned aerial vehicles, it may be prohibitive both in payload restrictions and payload space restrictions to install the necessary systems to receive information about the wind to determine a course correction angle for the wind.
Therefore, it would be desirable to have a method and apparatus that takes into account some of the issues discussed above as well as possibly other issues.